The Research Of High-Structure Carbon Black Morphology And Surface Activity

The high structure carbon black was widely used in the green tire. It can make the tire tread keep the property of the abrasion resistance and wet skid resistance, and at the same time, through reducing its rolling resistance to save fuel consumption and improve security. This thesis was mainly to study the surface nano-morphology of high structure carbon black, chemical structure of carbon black and the carbon black surface activity.(1)In this paper, the image of carbon black aggregate was tested by scanning probe microscopy by comparing the high structure carbon black with ordinary carbon black. The functions of MATLAB in image processing and numerical calculation were employed to process the images of the image into a binary and editing differential box-counting dimension program to measure the surface fractal dimension. The results showed that the surface of carbon black were smooth, and the aggregate distribution is relatively narrow, the morphology images of high structure carbon black aggregates showed a complex chain of support, compared to ordinary carbon black branch structure looks richer; The processing of fractal images by MATLAB is simple and convenient, and the calculating results of fractal dimensions tested by the Koch curve is accurate and believable. It were calculated that box-counting dimension of carbon black aggregates (model:N330, N550) and high structure carbon black aggregates (Model:CD2117, CRX2125) were1.5164,1.5070,1.5874,1.5774, and the greater of fractal dimension of the rock surface texture, the more complex of roughness.(2)In this thesis, the ordinary carbon black and high structure carbon black were heat-treated at different temperatures, and study the heat-treatment influence of surface functional groups of carbon black and bound rubber mass fraction. The results indicated that, with the temperature rising, the surface oxidation functional groups (carboxylic acid, phenolic hydroxyl group) of carbon black and high structure carbon black were shedding.The total content of acid declined when the temperature was going up. With temperature going up, the total acid amount of the surface of carbon black was reducing while the amount of bound rubber increasing.(3)Based on inverse gas chromatography, this paper studies the surface free energy of high structure carbon black and carbon black with the different specific surface area and oxygen functional groups. The dispersion free energy was increased with the specific surface area increases. The specific surface area of ordinary carbon black and high structure carbon black is proportional to the dispersion free energy. The dispersion free energy rises with the decrease of oxygen functional groups on carbon black surface by different heat treatment of high structure carbon black, while the dispersion free energy reduces with the increase of oxygen functional groups on carbon black surface by oxidation of high structure carbon black, which demonstrates that the oxygen functional groups are not the active centres of adsorption rubber.(4)Scanning probe microscope force curve was used to determined the different carbon black surface desorption force, and make data statistical analysis. Desorption force that tip was pulled away from the surface of the high structure carbon black was greater than ordinary carbon black’s, so did the chaos and the number of grains of high structure carbon black. The distribution of the surface microstructure and mechanical properties was explained via distribution of desorbed force values. AFM force curve was applied to study the microstructure and mechanical properties of the carbon black surface.